The sport of motor vehicle racing commenced shortly following the introduction of motorized vehicles. This holds true for motorcycles, the currently more popular racing venues involving dirt bikes driven over terrain courses wherein driver and bike typically are launched into airborne orientations over significant heights and distances. Sporting motorcycles were popular at the beginning of the 20th century. For instance, at that time Harley-Davidson marketed a lightweight bike powered by a 3-horsepower, 25-cubic inch one cylinder engine. Another racing model of that period utilized a V-Twin engine putting out 3½ horsepower. The 120 pound vehicle had a then innovative twist-grip throttle and could reach speeds of about 60 miles per hour.
While the current dirt bikes are being raced, the driver's feet will be engaging a foot support referred to as a “footpeg” extending rigidly outwardly from the frame. When these vehicles descend from a launch to impact terrain, traumatic forces often are imparted to the driver's legs through the footpegs notwithstanding the shock absorbers associated with the wheels of such vehicles.
In 1967, the American counterpart to a global motorcycle manufacturer requested the development of a vehicle that its dealers could sell during the winter season of slackening motorcycle sales. The result was the introduction of a 3-wheel all-terrain vehicle (ATV) that debuted in 1970. This original ATV exhibited a tricycle geometry and employed a 7-horsepower motorcycle engine to drive two rear twenty-two inch low pressure tires through a dual-range, four-speed gear box with an automatic clutch. The machine handled snow, mud and various slippery conditions which a motorcycle could not.
Further development optimized tire and chassis design and while the vehicles were considered basically a recreational device, multipurpose usage developed. A major interest for ATVs in the 1980s was racing, everywhere from frozen lakes in the East, to Western deserts, to dirt ovals in Middle America. Four-wheel machines were introduced in 1984 and were considered more versatile, particularly for utilitarian use. Inevitable accident statistics prompted the Consumer Product Safety Commission (CPSC) to mandate a four-wheel design. By 2001, the ATV industry was selling about 400,000 units per year.
Four-wheeled ATV vehicles utilized in racing are generally referred to as “sport quads”. Such sport quads incorporate two-wheel drive, somewhat expensive suspensions and more refined motors. Typically weighing about 370 pounds, the sport vehicles are quicker and more responsive than utility associated models. As in the case in dirt bike racing, when participating in a racing venue, the sport quads generally will from time-to-time be launched into an airborne orientation. During such performance, the driver's feet are supported upon the earlier-described footpegs extending rigidly outward from the vehicle frame. As before, when the sport-quads descend from a launch and impact the racing venue terrain, traumatic forces often are imported to the driver's legs through the footpegs, notwithstanding the shock absorbers associated with the forward wheels of the vehicle.